Student ID number consists of 6 characters. The first four

Juanita wants to buy 12.5 pounds of stones to decorate her garden. The stone normally sells for $1.80 a pound. The salesman offe

erica [24]

21.25 / 12.5 = 1.70 per lb

6 0

3 years ago

Read 2 more answers

Expression 3 + y and 2 (6+y) are equivalent?

Assoli18 [71]

Answer:

3+y and 12+2y

Step-by-step explanation:

I mean they aren't equivalent because if you do PEMDAS (parenthesis, exponents, multiply, divide, add, subtract) Then, you would do 2 times 6 because parenthesis, that equals 12 so the answer would be

3+y and 12+2y

6 0

3 years ago

5. Michelle feeds her fish 20 grams of fish food a day. How many kilograms of fish food does Michelle use in 8 weeks? Show your

ludmilkaskok [199]

Answer: (B) 1.12

Step-by-step explanation:

8 weeks = 56 days

56 days x 20 grams = 1120 grams

1120 grams = 1.12 kilograms

4 0

4 years ago

52. In exploring possible sites for a convenience store in a large neighborhood, the retail chain wants to know the proportion o

kvasek [131]

Answer:

$n=\frac{0.5(1-0.5)}{(\frac{0.1}{1.96})^2}=96.04$

Then the minimum sample size in order to satisfy the condition of 0.1 for the margin of error is 97 and since the sample used is n =100 we can conclude that is sufficient and the best answer would be:

D. Yes.

Step-by-step explanation:

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. We know that we require a 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

The margin of error for the proportion interval is given by this:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

We want a margin of error of $ME =\pm 0.1$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Since we don't have prior info for the population proportion we can use as estimator the value of 0.5. And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.1}{1.96})^2}=96.04$

Then the minimum sample size in order to satisfy the condition of 0.1 for the margin of error is 97 and since the sample used is n =100 we can conclude that is sufficient and the best answer would be:

D. Yes.

4 0

3 years ago

Find the standard deviation of the distribution in the following situations. (Round your answers to two decimal places.) (a) MEN

Arturiano [62]

Answer:

a) 15.579

b) 39.019

Step-by-step explanation:

a) For the top 2% the z-value from the z table

z = 2.054

thus,

z = $\frac{\textup{X-Mean}}{\sigma}$

here

X = 132

Mean = 100

thus,

2.054 = $\frac{\textup{132-100}}{\sigma}$

or

σ = 15.579

b) Using tables, we get for Z = 0.89 the value of 0.8133 and for Z= 0.90 the value of 0.8159

By interpolation, values for 0.815 and we get Z=0.897

thus,

z = $\frac{\textup{X-Mean}}{\sigma}$

here

X = 220

Mean = 185

thus,

0.897 = $\frac{\textup{220-185}}{\sigma}$

or

σ = 39.019

6 0

3 years ago